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i, @eine tats-e etent @time IMPROVEMENT IN BRIDGES.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, J. BUTTON STEL-ILE, of Pottstown` in the county of Montgomery, and Stute of Pennsylvania, have invented a new and improved Mode of Building 'Truss Bridges; and I do hereby declare that thc following is n. full and exact description thereof, reference beingr hnd to the accompanying drawing, and tothe letters of reference thereon.

The'nuture of my invention consists in so arranging the braces and counter-braces of truss bridges as'to dispense with the use oi' vertical posts and binding-rods.between the cords, and iny causing the braces and counterbraces to not :ts posts and binding-rods, by which ineens all the angles of thrust upon the cords are .inode equal, the absolute strain upon any one set of braces or eountenbruces is reduced one-half, perfect bearing forall the braces and counter-braces is obtained during the elnsticity which is caused by a moving load, and the full action of the counter-brnces in transferring the strain from one set of braces to another is secured. As :t consequence of these results'the amount ot' material in either series of braces may be reduced one-half, and nsthe truss is about :ts well adapted to resist upwards as downward str-nin, und the power to resist upward strain being n. corrective of the tendency to undulnte under moving` loads, `it is unusually stift" and all its material is in useful action. l

To enable others skilled in the a-rt of bridge building to niake'use of my invention I will proceed to describe its construction.

The cords may be either of wood or iron, in the usual mode, to connect which I employ a series of strut main braces, a at, and a series of brace-rods, b l, also. a. series of strut counter-braces, [l (I, either of wood or iron, and o series of counterbrace rods, c e, thus making n double series ot' diagonal braces, both main and counter, so arranged that the whole not only net as braces, but also perform the functions for which vertical posts and binding rods are usually employed. The strut counter-braces may be entirely dispensed with in4 bridges for ordinary travel, and a. portion of then'l may be left out in railroad bridges, without impniring the stability of the structure, or they nifty be retained und a portion of the counter-brace rods nitty be dispensed with as circumstances may dictate. i i

I do not` claim as my invention the use either of' a series of niain and counter-braces, in combination with vertical posts and vertical binding-rods, nor a. series of main and counter-brace rods in connection with vertical posts and vertical binding-rods, er their equivalents, but I do claim as my invention l The combination of the two series, substantially as set forth, or their equivalents, made either of wood Aor of iron, in the manner and for the'purpose hereinbei'ore described.

' J. BUTTON STEELE.

Witnesses:

Guo. BUCKLEY, JOHN WHITE. 

